Electric-tube lighting.



No. 702,3!6. Patented Iune I0, i902.

D. MGF. MURE ELECTRIC TUBE LIGHTING.

(Application filed Dec. 18, 1901.) (No Model.) Y

Figi

m: mams Pneus co., Fuero-umn.. wAsmemTcN. u. c.

ATENT GFFICE.

DANIEL MCFARLAN MOORE, OF NEWARK, NElV JERSEY.

ELECTRIC-TUBE LIGHTING.

SPECIFICATION forming part of Letters Patent No. 702,316, dated J une 10, 1902.

Application filed December 18,1901. Serial No. 86,359. (No model.)

To all whom, t may concern:

Beit known that I, DANIEL MCFARLAN- MOORE, a citizen of theUnited States, and a resident of Newark, in the county of Essex and State of New Jersey, have invented certain new and usefullmprovemeuts in Electric- Tube Lighting, of which the following is a specification.

My invention relates to those systems of electric lighting wherein the light-giving body consists of acolumn of rareed gas or vapor, through which the electric energy is passed from conducting-electrodes at the terminals of said column, said electrodes consisting, preferably, of caps or sleeves of conducting material closely-adherent to or in close contact with the exterior surfaces of a translucent tube or receptacle containing a column of gas to be rendered luminous and to which the energy is transferred from said caps by electrostatic action taking place through the glass walls.

I have heretofore described in previous patents systems of lighting employing light-giving bodiesof this character wherein the electric energy consists of alternating electromotive force of comparatively high frequency and preferably of peculiar form when graphically represented. In my Patent No. 644,095 I have setout a construction of generator designed to give an electromotive force'of abruptly-changing value, and in said patent have stated that in practice good results may be obtained by using afrequency of approximately forty-eight thousand periods per minute. In another patent issued to me on the same date and numbered 645,041 I have stated that with a voltage of about six thousand and a frequency of about fty thousand periods per minute lamps of the character above described maybe rendered luminous to an extentsuited for commercial use by directly -applied alternating electromotive forces from a suitable alternating generator adapted to furnish such frequences and voltage.

Neither of the systems already described contemplate the use of alternating currents such as are employed commercially for the distribution of power and lightthat is to say, alternating currents of a frequency as low as seven thousand two hundred alternations per minute-and it has hitherto been considered by those skilled in the art impossible to obtain commercial illumination from lamps of the character above stated by the use of such low frequencies. I have, however, discovered that if the lamp be provided with a conducting cap or terminal of a denite area wit-h relation to the length of the luminous column between the conductingcaps it is possible to secure an effective illumination by the use of the ordinary sinusoidal electric currents of as low a frequency as seven thousand two hundred or even lower, such as are supplied to ordinary alternatingcurrent mains by which electricity is distributed for power and light; and my invention accordingly consists in a novel electriclighting system comprising lamps of the general character above stated and alternatingcurrent power-mains carrying currents of the ordinary commercial frequency and of sinusoidal form, supplying energy to said lamps directly or indirectly, but preferably through the intervention of a potential-raising converter.

In the accompanying drawings, Figures l and 2 are general diagrams illustrating the system, and Fig. 3 shows the form of alternating current upon the power-mains.

In the drawings the mains areindicated by the numeral l and may be the ordinary streetmains leading from a power-house and carrying sinusoidal currents which furnish electricityfr power and light.`

2 indicates a potential-raising converter, preferably a static transformer, which if the power-mains have a Voltage of the ordinary amount-say two thousand volts-and a frequency of, say, seven thousand two hundred periods per minute would be preferably constructed to raise the voltage to, say, from five thousand to nine thousand volts. It is sufiicient to say that the larger the area of the caps or terminals upon the lamps the less the voltage required to excite the column of rareed gas to what would be regarded as acommereial density of luminosity.- I have obtained in practice satisfactory results by using tubes and caps of the proportions shown. Thus, for instance, I may use a tube, say, ninety-one inches long and having conducting caps or terminals of sixteen inches in IOO length, in which case it would be desirable to employ a voltage on the secondary of about nine thousand. It is, however, possible to use longer caps, in which case satisfactory results may be obtained by using lower voltage, and by correspondingly increasing the length of the cap the voltage may be still further lowered. With tubes, however, which are of such length as to be readily handled and are not more than ninety-one inches long it is not desirable to increase the length of the cap to any considerable extent for the purpose of decreasing the Voltage required, since the caps then so far obscure the luminous column or cover it up that a point is soon reached where, although the voltage may be lower, the efficiency of the lamp is reduced to a prohibitory degree. It will be seen, therefore, that it is not possible to set any definite limits to the voltage which would be within my present invention, excepting so far as the voltage may be determined, as above stated, by the length of cap, which in turn is determined bythe length of tube which is employed for the lamp. As already stated, however, by giving proper attention to the length of the cap, so as to permit the proper amount of energy to be transferred to the gaseous contents, it becomes practicable to employ in the system the ordinary alternating-current street-circuits with their established commer-y cial frequency and voltage of current.

I have mentioned a frequency of seven thousand two hundred on the mains; but it is to be understood that lower frequencies could be employed, but with a corresponding increase either in the voltage supplied to the terminals of the lamps or in the size of the caps, or both.

If the voltage of the' sinusoidal-current mains be high enough, the transformer may be dispensed with and the caps connected directly to said mains. y

Sindicates the glass tube, which contains the rarefied gas or vapor, which is acted upon by the electric energy and rendered luminous.

4 indicates the conducting caps or terminals thereof, which may be applied in any desired way, but preferably formed in the manner already set forth by me in my prior patents, and are made of conducting material which is closely adherent to or in close contact with the exterior surface of the glass tube.

Connection to the terminal caps or electrodes is made from the secondary of the transformer in any desired way, and a large number of lamps may be supplied in multiple from the secondary, as shown in Fig. 2,

where they are shown disposed near the ceiling of the room or apartment to be lighted, or they may be connected to said transformer in any of the ways usual in electric engineering. So, also, the transformers may be connected to the mains in multiple in any desired number.

The gas or vapor in the lamps may be of any character suited to the purpose, and the degree of gaseous tension or rarefaction of the contents may be such as is dictated by choice or convenience and as well understood in the art.

The invention claimed isl. The novel system of electric lighting herein described, comprising lamps consisting of sealed tubes of glass containing a rare- .fied gas or vapor and provided with conducting caps or terminals such as described, in combination with alternating-current supplymains furnishing alternating currents of established commercial frequency and voltage substantially as herein set forth.

2. The system of electric lighting hereinbefore described, and comprising electric lamps which consist of tubes of glass containing a rarefied gas and provided with conducting-electrodes as set forth, and alternating-current mains carrying alternating currents of the commercial frequency and voltage as described, and a potential-raising transformer interposed between said mains and the lamps.

3. The system of electric lighting hereinbefore described and comprising electric lamps which consist of tubes of glass containing a rareiied gas and provided with eX- terior conducting caps or devices such as described, and alternating-current mains carrying alternating currents of the commercial frequency and voltage as described, and a potential-raising transformer interposed between said mains and the lamps.

Li. The novel system of electric lighting herein described, comprising lamps consisting of sealed tubes of glass containing a rareiied gas or vapor and provided with conducting caps or terminals such as described, in combination with an alternating-current dynamo source furnishing alternating currents of definite frequency and voltage the area of said conducting caps or terminals being proportioned to said frequency and voltage.

Signed at New York city, in the county of New York and State of New York, this 16th day of December, A. D. 1901.

DANIEL MCFARLAN MOORE. Witnesses:

E. L. LAWLER, H. C. TowNsnNn.

IOO

IIO 

